2019-01-21T21:40:27ZOptimization of reverse logistics network of End of Life Vehicles under fuzzy supply: A case study for Istanbul Metropolitan Area (Article in Press)https://hdl.handle.net/20.500.12154/594
Optimization of reverse logistics network of End of Life Vehicles under fuzzy supply: A case study for Istanbul Metropolitan Area (Article in Press)
Kuşakçı, Ali Osman; Ayvaz, Berk; Cin, Emine; Aydın, Nezir
Recycling aims at preventing rapid depletion of natural resources while transforming produced waste into value for economy. However, this process becomes a major challenge in automotive industry, which requires cooperative engagement of multiple players within a complex supply chain. In line with the essence of the topic, government agencies around the world issue directives drawing regulatory frameworks for designing recycling operations comprising various activities such as collection of end-of-life vehicles (ELVs), recovery of reusable components, shredding ELV's body, recycling valuable materials and disposal of the hazardous waste. In general, the amount of returned product in a reverse logistics network is highly uncertain, and the ELV market in Turkey is no exception to this. For that purpose, this study aims developing a fuzzy mixed integer location-allocation model for reverse logistic network of ELVs conforming to the existing directives in Turkey. Accordingly, this study uses a novel approach and assumes that ELV supply in the network is uncertain. The merit of the proposed mathematical model is proved on a real world scenario addressing the reverse logistics design problem for ELVs generated in metropolitan area of Istanbul. The network generated specifies that recycling process is not profitable under the existing circumstances with the given level of supplied ELV and the returned product records per capita in Istanbul are far beyond the EU averages. Consequently, sensitivity analyses question the reliability of the obtained results.
Ali Osman Kuşakçı (IHU Author)
2019-01-01T00:00:00ZThe role of objective and subjective experiences, direct and media exposure, social and organizational support, and educational and gender effects in the prediction of children posttraumatic stress reaction one year after calamityhttps://hdl.handle.net/20.500.12154/555
The role of objective and subjective experiences, direct and media exposure, social and organizational support, and educational and gender effects in the prediction of children posttraumatic stress reaction one year after calamity
Bulut, Sefa
The purpose of this study was to test the direct, indirect, objec-tive, and subjective exposure effect on the development of Post Traumatic Stress Disorder (PTSD). The impact of social and organizational support, as well as age and gender factors, were examined in development of PTSD. Participants were 270 disaster survivor elementary and secondary school students. One year after the disaster, each participant filled out a Children’s Post-Traumatic Stress Disorder Reaction Index (CPTSD), trauma exposure, trauma experiencing, social support, and organizational support scales. Male and female students were compared on these instru-ments with univariate Anova. Elementary school children outscored both on the organizational support and trauma scale and this reached signifi-cance level. Additionally, contributing factors were predicted with a step-wise regression analysis. A combination of direct, indirect, objective expo-sure scores, subjective exposure scores, gender, age, organizational and so-cial support variables accounted for 17 % of the PTSD scores. Direct ex-posure accounted for 6 %, subjective exposure 5.4 %, age 3 %, having a friend moving away 2.6 % and food shortage contributed 1 %, and of the total variance. Direct exposure appeared to be the most significant predic-tors, followed by subjective exposure. Media exposure, gender, and physi-cal exposure seemed to be especially poor contributors. Neither school nor home damage, the death of relatives or friends, or gas, water, and elec-tric shortages contributed significantly to the results.; El propósito de este estudio fue evaluar el efecto de la exposi-ción directa, indirecta, objetiva y subjetiva en el desarrollo del Trastorno de Estrés Postraumático (DEPT). El impacto del apoyo y la organización so-cial, así como el efecto de la edad y el género, fueron examinados en rela-ción con el desarrollo de DEPT en este grupo. Los participantes fueron 270 estudiantes de escuela elemental y secundaria sobrevivientes al desas-tre. Un año después, cada participante completó el Índice de Reacción al Trastorno de Estrés Postraumático (Children’s Post-Traumatic Stress Di-sorder Reaction Index, CPTSD), exposición al trauma, apoyo social y la escala de apoyo organizacional. Los factores participantes se predijeron por medio de un análisis de regresión stepwise. Una combinación de punta-jes de exposición directa, indirecta, objetiva y subjetiva, género, edad, apo-yo social y organizacional explicó el 17 % de los puntajes de DEPT. La ex-posición directa explicó un 6 %, la exposición indirecta el 5.4 %, edad 3 %, falta de alimento el 1 %, y tener un amigo que se cambió de lugar de vi-vienda después del desastre contribuyó en la explicación de un 2.6 % de la varianza total. La exposición subjetiva y la exposición directa parecen ser los principales predictores. Sin embargo, contrario a los hallazgos de estu-dios anteriores, la exposición a los medios, el género y la exposición física aparecen como pobres predictores. Ni los daños a la escuela o a la casa, la muerte de familiares o amigos o la falta de acceso a servicios como el gas, el agua o la energía contribuyeron significativamente a los resultados.
Bulut, Sefa (IHU Author)
2018-01-01T00:00:00ZBusiness analytics and firm performance: The mediating role of business process performancehttps://hdl.handle.net/20.500.12154/550
Business analytics and firm performance: The mediating role of business process performance
Aydıner, Arafat Salih; Tatoğlu, Ekrem; Bayraktar, Erkan; Zaim, Selim; Delen, Dursun
Due to the rapidly increasing popularity of business analytics (BA), investigation of the antecedents/determinants of the adoption of BA and the subsequent impact of the same to the firm performance has become an important research topic. Drawing on the fundamentals of the resource-based view (RBV), this study proposes a model that examines the effects of the BA adoption on business process performance (BPER) and the mediating role that BPER plays in the relationship between the adoption of BA and firm performance (FP). Based on the data collected from 204 medium- to high-level business executives in various industries, the results of this empirical study indicate that the adoption of BA positively influences BPER. There is also positive relationship between BPER and FP. Finally, the results show that BPER fully mediates the relationship between BA adoption and FP.
Tatoğlu, Ekrem (IHU Author)
2019-01-01T00:00:00ZA relational view of environmental performance: What role do environmental collaboration and cross-functional alignment play?https://hdl.handle.net/20.500.12154/502
A relational view of environmental performance: What role do environmental collaboration and cross-functional alignment play?
Gölgeci, İsmail; Gligor, David M.; Tatoğlu, Ekrem; Ayaz Arda, Özlem
Despite extensive research into the role played by social capital and relational capability in attaining interorganizational advantage, the way in which these resources matter for environmental performance has received scant attention. We investigate how firms' social capital and relational capability influence their environmental performance, by analyzing the mediating role of environmental collaboration and the moderating role of crossfunctional alignment. Based on an analysis of dual responses from 270 Turkish firms, we find that environmental collaboration mediates the impact of social capital and relational capability on environmental performance. We also find that alignment between marketing and supply chain management functions strengthens the effects of relational capability and environmental collaboration on environmental performance. Our study suggests that both environmental collaboration and cross-functional alignment are necessary if the true value of social capital and relational capability for environmental performance is to be realized.
Tatoğlu, Ekrem (IHU Author)
2019-03-01T00:00:00Z